1. Field of the Invention
The invention relates to control of a motive power apparatus for a hybrid vehicle equipped with a plurality of kinds of prime movers that include a rotary electric machine.
2. Description of Related Art
A hybrid vehicle equipped with an internal combustion engine and a rotary electric machine as prime movers for driving the vehicle is known. In this specification, the term “rotary electric machine” is used as a collective term for electric motors, electric generators, and electric appliances that function as both an electric motor and an electricity generator. A rotary electric machine has coils that have been obtained by winding conductive wires. A conductive wire of such a coil has on its surface a coat layer of an electrical insulator, which achieves electrical insulation between conductive wires or between coil windings. However, if the potential difference between adjacent conductive wires exceeds an insulation permissible voltage of the coat layer, electric discharge between conductive wires starts.
The electrical insulation permissible voltage of the coil, that is, the electric discharge-starting voltage, changes depending on the temperature of the coils and the ambient air pressure. Japanese Patent Application Publication No. 2010-252572 (JP 2010-252572 A) describes an art in which electrical insulation of a coil is secured by controlling the electric power to be supplied to a rotary electric machine or the electric power generated by a rotary electric machine on the basis of the coil temperature and the ambient air pressure.